ApoE [-/-] CA1-overexpressing knock-in mice aggravated atherosclerosis by increasing M1 macrophages.

BACKGROUND

Carbonic anhydrase I (CA1) has been reported to be a diagnostic and therapeutic target for atherosclerosis (AS). This study aimed to verify the essential role of CA1 in AS progression in CA1-overexpressing mice.

METHODS

A ApoE [-/-] CA1-overexpressing knock-in mouse model was constructed via CRISPR/Cas9-mediated genome engineering. AS was then induced in these transgenic mice via the administration of a high-fat diet, and a second group simultaneously received treatment with methazolamide (MTZ), a carbonic anhydrase inhibitor.

RESULTS

Compared with ApoE [-/-] mice without CA1 overexpression, CA1-overexpressing mice had a greater average body weight, regardless of whether their treatment with MTZ or their AS induction status. Sudan IV, hematoxylin and eosin and Oil Red O staining revealed more plaques and fat deposits in the cardiac aortas of CA1-overexpressing mice than in those of ordinary ApoE-/- mice when AS was induced. Moreover, the atherogenic index; low-density lipoprotein, total cholesterol and triglyceride levels were significantly elevated, and high-density lipoprotein levels were declined in the peripheral blood of CA1-overexpressing mice than in that of ordinary ApoE [-/-] mice, regardless of whether these animals were induced to AS. Immunohistochemistry, staining and fluorescence immunohistochemistry revealed increases in CA1 expression, calcium deposition and M1 macrophages in the aortic tissues of CA1-overexpressing mice with AS. MTZ treatment significantly suppressed AS pathologies in the above experiments.

CONCLUSION

These findings revealed aggravated AS in ApoE [-/-] CA1-overexpressing mice and suggest that CA1 aggravates AS by increasing M1-type macrophages, a proinflammatory macrophage subtype.